Optimised activation of bentonite for toluene adsorption

Effect of Hydrochloric Acid on the Structural of Sodic-Bentonite Clay

“…These variations, thus, have led to decrease in the density of acid treated bentonite as the particulate volume automatically increases and therefore decreases the specific gravity. According to Amari et al [23], in the line with the previous results reported by Morgan et al and Kheok and Lim [36] [37], state that the surface increases with the increase of acid concentration to the optimal value, beyond this acid concentrations the surface decreases. The SEM micrograph of activated bentonite with HCl 0.6 N shows the diminution of proportions of the different grains of size located between 60 µm and 200 µm.…”

“…By increasing the hydrochloric acid concentration from 0.05 to 0.6 M, there was an increase in SiO 2 content in bentonites, but the increase was more at higher acid concentration. The same behavior is observed in the ratio of Si/(Al + Fe + Mg) which was increased in bentonite until treatment with 0.6 M. Bentonite activation with hydrochloric acid has caused an increase of the SiO 2 content due to remobilization of octahedral cations [21]- [23]. Octahedral cations have shifted into the solution while the silicon, owning to its insolubility, remained and its content has increased with the increase of HCl concentration.…”

Effect of acid activation of Saudi local clay mineral on removal properties of basic blue 41 from an aqueous solution

“…However, the samples MtKhl − 0.3 to MtKhl − 0.5 exhibited different shape that the other clay minerals and adsorbed more nitrogen than the original MtKhl. They corresponded to type IV, characteristic of mesoporous materials (Amari et al, 2010). The desorption isotherms exhibited hysteresis phenomena with different shapes, depending of the acid activated levels, as presented in Fig.…”

“…The acid treatment firstly rendered the surface of clay mineral acidic, then it leached metal ions from the clay mineral lattice leading to an increase of the external surface area of the clay mineral and introduces permanent mesoporosity (Jozefaciuk and Sarzynska, 2006). The extent of these changes depended on different parameters such as the geographical origin of the clay mineral, the type of the used acid, its concentrations, temperature and time of acid activation (Noyan et al, 2007;Amari et al, 2010;Komadel and Madejová, 2013;Kooli and Liu, 2013). These acid activated clays have found many applications in industrial process such as the decolorization of the vegetable oil in edible oil industry (Temuujin et al, 2006;Nguetnkam et al, 2008;Didi et al, 2009) and as adsorbents for heavy metals and dyes (Eren and Afsin, 2008;Yener et al, 2012).…”

Adsorption of organic matter from industrial phosphoric acid (H 3 PO 4 ) onto activated bentonite

“…Acid-activation (Amari et al, 2010) was carried out with sulfuric acid (1.5 M) in a jacketed glass reactor equipped with a reflux condenser, a thermometer and a stirrer. At the end of each experiment, the solid content was immediately filtered, washed free of sulfate with hot water until the washing water was neutral, and dried at 110°C for a few hours, in order to obtain dehydrated samples and a constant weight.…”